Minimize Transporter-2

Transporter-2 — Second Rideshare mission of SpaceX

Payload Manifest    References

A SpaceX Falcon 9 rocket launched the Transporter-2 satellite on June 30, 2021 on the company's second dedicated smallsat rideshare mission. 1)

The Falcon 9 lifted off from Space Launch Complex 40 at Cape Canaveral Space Force Station at 3:31 p.m. EDT (19:31 UTC), more than halfway into a nearly hourlong launch window because of weather. A launch attempt the day before was scrubbed when a private helicopter entered restricted airspace minutes before the scheduled liftoff.


Figure 1: A SpaceX Falcon 9 lifts off June 30 on the Transporter-2 rideshare mission, with 88 satellites on board (image credit: SpaceX webcast)

Deployment of the payload of 88 satellites started nearly 58 minutes after liftoff, once the upper stage performed a second burn of its engine to place it into a sun-synchronous orbit at an altitude of nearly 550 kilometers. The satellites, from a variety of government and commercial customers, were released over half an hour.

The mission, named Transporter-2 by SpaceX, was the company's second dedicated smallsat rideshare mission, after the Transporter-1 mission in January. The earlier flight carried 143 satellites, but SpaceX said the total payload mass for Transporter-2 was greater than that of Transporter-1. The company did not disclose specific payload mass figures for either mission.

SpaceX established its smallsat rideshare program nearly two years ago, offering low-cost launches on dedicated Falcon 9 missions like Transporter-2 as well as on launches of its Starlink satellites. It has attracted significant interest from both companies and government agencies.

The Transporter-2 payload manifest featured synthetic aperture radar (SAR) satellites from three competing companies: Capella, ICEYE and Umbra. HawkEye 360 and Kleos, two companies deploying constellations to perform radio-frequency tracking, each had satellites on this mission, as did PlanetiQ and Spire Global, which collect GPS radio occultation data for use in weather forecasting.

Other commercial customers included Astrocast and Swarm, which are each developing internet-of-things constellations, and Satellogic, which has a multi-launch agreement with SpaceX for launching its imaging satellites. SpaceX flew three of its own Starlink satellites on the launch, which will join 10 Starlink satellites launched into polar orbit on Transporter-1.

The Pentagon's Space Development Agency (SDA) had four satellites on Transporter-2. Two Mandrake-2 satellites — originally intended to launch on Transporter-1 before being damaged in prelaunch processing — feature optical crosslinks and will be used to test technologies for future low Earth orbit military satellite. Two CubeSats built by General Atomics will also test optical communications between satellites and with drones. SDA has a fifth payload on Loft Orbital's YAM-3 satellite.

NASA flew two smallsats on Transporter-2, including a pathfinder for a CubeSat constellation called TROPICS (Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats). TROPICS Pathfinder is identical to the six TROPICS satellites that Astra will launch on its Rocket 3 small launch vehicle in 2022 and will enable full testing of the satellite design in advance of the deployment of the constellation.

Many of the customers worked with launch services providers such as D-Orbit, Exolaunch and Spaceflight. That included two Sherpa tugs from Spaceflight on this launch, one of which has electric propulsion from Apollo Fusion.

Launch cadence and reusability

Transporter-2 was SpaceX's 20th Falcon 9 mission of the year, with six months yet to go. In only two years has SpaceX conducted more orbital launches: 21 in 2018 and 26 in 2020. The company is on track to shatter the record set last year, even with an anticipated slowdown of launches in July and August.

A key factor in that high launch cadence is reusability. The Falcon 9 booster used for Transporter-2 was making its eighth flight, concluding with a landing at Cape Canaveral's Landing Zone 1. Its first launch was exactly one year ago, when it launched a GPS 3 satellite, and was also used for launching Turksat 5A and five Starlink missions before Transporter-2. Other Falcon 9 boosters have flown up to 10 times.

While SpaceX previously set a goal of 10 flights per booster, company officials have in recent months suggested those boosters could fly more than 10 times. "We've got boosters now that have flown 10 times, and some that are slated to fly 20 or possibly 30 times," Elon Musk, founder and chief executive of SpaceX, said in a June 29 appearance at the Mobile World Congress.

"With Falcon 9, we've achieved I think the most efficient reusability of any rocket to date," he said, but added that SpaceX will take reusability "to another level" with its Starship vehicle. That vehicle, whose first orbital launch Musk now says will take place in the "next few months," is intended to be reflown without any significant refurbishment, like an airliner.

"The Holy Grail for rocketry is rapidly reusable reliable rockets," he said.

Transporter-2 Mission Launch Rewatch and recovery of the Falcon 9 first stage as provided by SpaceX 2)

On June 30 at 3:31 p.m. EDT, Falcon 9 launched the Transporter-2, SpaceX's second dedicated SmallSat Rideshare Program mission, from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida. The mission also marked SpaceX's second launch to a polar orbit from Florida. This was the eighth launch and landing of this Falcon 9 first stage booster in exactly one year, including launch of GPS III Space Vehicle 03, Turksat 5A, and five Starlink missions. Following stage separation, SpaceX landed Falcon 9's first stage on Landing Zone 1 (LZ-1) at Cape Canaveral Space Force Station.

On board this launch were 85 commercial and government spacecraft (including CubeSats, microsatellites, and orbital transfer vehicles) and 3 Starlink satellites. While there were fewer spacecraft on board compared to Transporter-1, this mission launched more mass to orbit for SpaceX's customers.


Figure 2: Artist's illustration of the early launch phase and recovery of the Falcon 1st stage (image credit: SpaceX)

The first stage of the Falcon 9 vehicle has a length of 41.2 m, a diameter of 3.7 m, and an empty mass of 25,600 kg. Hence, a recovery and multiple reuse of the first station is rather advantageous for the launch service provider, resulting in lower launch costs for the customer.


Figure 3: Return of the Falcon 9 1st Stage to the Landing Zone (image credit: SpaceX)


Transporter-2 Payload Manifest

Spaceflight Inc., a launch service provider based in Seattle, Washington, had three ports for their SXRS-5 mission holding two of their Sherpa deployers and customer payloads totaling 7 microsatellites and 29 CubeSats, along with one hosted payload. One port hosted the Sherpa-FX2 free-floating deployer with 21 CubeSats, three microsatellites, and the TagSat-2 hosted payload. Another port hosted Loft Orbital's YAM-2 satellite. 3)

The last Spaceflight Inc. port hosted their first OTV (orbital transfer vehicle), Sherpa-LTE1, with an electric propulsion system to allow orbit changes. The Sherpa-LTE and Sherpa-LTC variants add solar panels, a propulsion system, and an avionics/attitude control box to the Sherpa-FX framework. As seems to be both usual and prudent with the first test flight of an OTV, Spaceflight released all of the customer payloads from the Sherpa-LTE before exercising the new propulsion, power generation, communications, and attitude control systems. At the end of the year, the company is scheduled to fly their first Sherpa with a chemical propulsion system, Sherpa-LTC1.

D-Orbit, an Italian launch service provider, has named their mission "Wild Ride". They rode their third OTV, ION SCV-003 "Dauntless David". The vehicle carried six CubeSats and three hosted payloads. Several of the payloads are in a deployer from another launch service provider, Netherlands based ISILaunch. After deploying the customer satellites, D-Orbit will test payloads dealing with optical communications (LaserCube), on-orbit computing for artificial intelligence and machine learning applications (Nebula), and using machine learning for flood detection (Worldfloods). At the end of the mission they will test a small (1U size) deorbit sail.

Some of payloads deployed on the mission include three of SpaceX's Starlink communication satellites.

Maverick Space Systems again had a deployer mounted to the aft end of the Falcon 9 second stage of Transporter-2, as they did on the earlier Transporter-1 mission. They launched two CubeSats for NASA, TROPICS Pathfinder (3U CubeSat) and PACE-1, a 6U CubeSat.


Table 1: Overview of the Payload Manifest on the Transporter-2 mission

Exolaunch: The Exolaunch service provider of Berlin, Germany, named its launch campaign ‘Fingerspitzengefühl' 4) by integrating 29 small satellites its launch campaign from the USA, Europe and South America. With a combined mass of close to one ton, Exolaunch doubles its mass capacity from SpaceX's previous rideshare for small satellites, making ‘Fingerspitzengefühl' its largest mission in terms of payload mass to date. This will also be one of the most diverse rideshare missions for the company bringing the total number of satellites launched by Exolaunch to 170. 5)


Figure 4: An artist's impression of the Exolaunch's Fingerspitzengefühl satellites deployment into orbit (image credit: Exolaunch)

Exolaunch's rideshare cluster includes payloads with cutting-edge technologies for IoT, Earth Observation and scientific applications, and satellites from its international customers such as Loft Orbital, NanoAvionics, ICEYE, and the TU Berlin. Exolaunch is also providing flight hardware, separation systems and integration services to support Satellogic's four microsatellites on this mission.

"‘Fingerspitzengefühl' on Transporter-2 symbolizes Exolaunch's vast experience in successfully deploying our customers' satellites into orbit," said Medvedeva. "It's also a continuation of the individual mission names that started with ‘Zeitgeist', literally ‘Spirit of the Time', Exolaunch's previous rideshare launch aboard SpaceX's Falcon 9 in January 2021."


Figure 5: Satellogic's satellites integration with EXOport (image credit: Exolaunch)

Earth sensing applications were also well represented. Satellogic had four of their ÑuSat optical observation satellites with both high resolution and hyperspectral imagers on the flight (Ref. 3).

Orbital Sidekick's Aurora hyperspectral imaging satellite is a precursor to their upcoming GHOSt constellation. TU Berlin has their TUBIN satellite with a thermal infrared imager. NAPA II for the Royal Thai Air Force is an optical imaging CubeSat with two cameras. Aerospacelab's Arthur-1 is a tech demo for a future optical imaging constellation while PAINANI-II from CICESE is a demo imaging CubeSat.

For synthetic aperature radar (SAR) enthusiasts, the first satellite from SAR provider Umbra was onboard (65 kg microsatellite), as is another Capella constellation satellite (~110 kg) and four more satellites for the ICEye constellation.

For the signals intelligence market, Kleos launched four more of their 6U CubeSats that fly in formation to locate Radio Frequency sources, and Hawkeye 360 launched three more of their Hawk microsatsatellites that perform a similar function. The Neptuno test satellite from Deimos also has a similar purpose.

Spire Global had six more of their Lemur-2 3U CubeSats that perform radio occultation measurements to aid weather forecasting as well as having receivers for maritime AIS and aviation ADS-B signals to track ships and planes. PlanetiQ has its GNOMES-2 radio occultation satellite on board (30 kg microsatellite).

There were a number of satellites on the flight for IoT (internet of things) applications. Echostar is hoping to secure its spectrum rights with a successful deployment of the EG-3/Tyvak-0173 CubeSat. OQTech has the Tiger-2 CubeSat. Expansions of existing IoT networks include Fleet (Centauri 4/Tyvak-0211), Astrocast (five more 3U CubeSats), and Swarm (with two dozen or more of their tiny .25U SpaceBEE CubeSats).

One of two companies seeking to connect satellites directly to cell phones, Lynk, has their Lynk-06 "Shannon" microsatellite on the flight. W-Cube from Reaktor Space will test W-band communications.

Two pairs of satellites for the Space Development Agency (along with DARPA and AFRL) will test optical communications links. Mandrake 2A and 2B from Astro Digital were originally scheduled to fly on Transporter-1 but were damaged during payload processing and delayed to this flight. LINCS A & B 12U CubeSats were manufactured by General Atomics EMS and also have an infrared payload.

The UAE's (United Arab Emirates) Ghalib CubeSat will allow tracking of falcon migrations. University of Toronto's HERON MKII will host a biological experiment to study the effects of microgravity on a yeast found in human gut flora. QMR-KWT, Kuwait's first CubeSat, will allow students to upload code to be run on the satellite.

Spaceflight SXRS-5 (SpaceX RideShare mission-5) 6)

Spaceflight secured 3 ports on the mission to support 36 spacecraft — comprised of 6 microsatellites, 29 CubeSats and one hosted payload — from 14 organizations across 7 countries. To say handling the launch services and mission management is complex for a mission this size is an understatement, but it's truly what we love to do.

• Aerospacelab's Arthur 12U CubeSat: Aerospacelab's Risk Reduction Flight mission objective is to put into service a high resolution optical payload, gain flight heritage for the in-house developed equipment, and verify the capability to maneuver the spacecraft thanks to the Micro Propulsion System from ExoTrail.

• Astrocast's IoT Nanosatellites: Astrocast will be launching an additional 5 IoT Nanosatellites (3U CubeSats) to its constellation. The Astrocast SatIoT Service enables companies to track IoT Assets in some of the world's most remote regions.

• HawkEye 360's Cluster 3: The Cluster 3 launch further expands HawkEye 360's next-generation satellite constellation, which detects and geolocates radio frequency signals. The Cluster 3 satellites are able to collect a greater quantity of data across a wider portion of the RF spectrum, creating valuable, actionable insights for maritime domain awareness, national security, environmental protection and more.

• In-Space Missions Limited's Faraday Phoenix: In-Space Missions are world-class experts who design, build and operate bespoke physical and digital customer missions from their UK offices.


Figure 6: Illustration of the Faraday Phoenix 6U CubeSat mission (image credit: In-Space)

• Kleos Space's Polar Vigilance Mission cluster of four 6U CubeSats: The four satellite Polar Vigilance Mission from Kleos will deliver radio frequency Earth Observation data.

• Loft Orbital's YAM-2: Loft Orbital's satellite is flying several missions for commercial and government customers.

• Lynk Global Inc.'s Shannon: Lynk's microsatellite mission is to provide global ubiquitous connectivity to unmodified mobile phones and cellular devices.

• NearSpace Launch Inc.'s TagSat-2: TagSat-2 mission is built by NearSpace Launch to provided 24/7 telemetry while hosting payloads for experimental testing.


Figure 7: Illustration of the TagSat-2 6U CubeSat (image ccredit: Nearspace)

• OQ (Omar Qaise) Technology's TIGER-2 5G IoT: The TIGER-2 mission is OQ Technology's second mission that aims to start commercial service by providing global 5G IoT connectivity to customers using a 6U high power satellite and to secure strategic frequencies. The mission carries two telecom payloads: The primary payload will provide satellite-based IoT and M2M services using low frequencies, and the secondary payload will demonstrate the feasibility of using high frequencies for 5G radio links.


Figure 8: OQ Technology's TIGER-2 5G IoT 6U CubeSat (photo credit: OQ Technology and Nanoavionics)

• Orbit Fab's Tanker-001 Tenzing: Orbit Fab's first operational fuel depot will provide propellant for the fast growing in-orbit servicing industry.


Figure 9: Orbit Fab's Tanker-001 Tensing microsatellite (35 kg) in orbit (image credit: Orbit Fab)

• Orbital Sidekick Inc.'s Aurora mission, San Francisco: The Aurora microsatellite mission (~22.5 kg) begins scalable delivery of commercial solutions using space-based hyperspectral imaging. Astro Digital built and is operating the satellite for Orbital Sidekick (OSK). The Aurora satellite will serve OSK's customers in the energy, mining, and defense sectors, including expanding contracts and pilot program opportunities for oil and gas pipeline monitoring & methane mapping, clean energy resource exploration, sustainable mining practices, and wildfire risk mitigation.


Figure 10: Two views of Orbital Sidekick's Aurora microsatellite mission (image credit: Orbital Sidekick)

• Spire Global Inc.'s Lemur-2: The Lemur–2 satellites collect Earth data to provide some of the most advanced maritime, aviation, and weather tracking in the world. The Lemur–2 also supports hosted software and payloads through Spire Space Services. 7)

- Three more nanosatellites have been launched as part of ESA's efforts to boost the European space industry, fostering innovation and creating jobs.

- The satellites will be used to monitor climate change, forecast the weather, track ships at sea and aeroplanes in flight, and connect electronic devices to one another through the internet of things, enabling people to stay connected to one another everywhere and all the time.

- They were launched as part of ESA's Pioneer Partnership Program, with support from the UK Space Agency, which aims to boost entrepreneurism by helping relatively small companies to demonstrate how new and advanced telecommunications technologies can work in space and provide new commercial services.

- Two of the satellites, equipped with terminals enabling optical inter-satellite links, were developed by Spire, a UK-based data and analytics company that uses a constellation of nanosatellites to track weather patterns, and follow maritime and aviation traffic.

- The third nanosatellite was developed by In-Space Missions (see above), a satellite manufacturer based in the UK that offers rideshares for companies that seek to quickly demonstrate their technologies without having to organize their own launches. The spacecraft will support eight different payloads from companies including Lacuna Space and SatixFy, both based in the UK.

- Some 15 satellites are already operational in orbit, thanks to the Pioneer Partnership Program, and a further 12 satellites are due to be launched in the coming two years.

- Established in 2017, the Pioneer Partnership Program enables the European and Canadian space industries to validate new technologies and services in orbit, in a timely and cost-effective manner.


Figure 11: A deployed Lemur-2 3U CubeSat (image credit: Spire Global)

• Swarm Technologies' SpaceBEES: Swarm's 1/4U satellites are the smallest 2-way commercial communications satellites in the world, and are used to provide low-cost, global connectivity to remote IoT devices.


Figure 12: Illustration of some 0.25U SpaceBEE CubeSats (image credit: Swarm Technologies)



TROPICS Pathfinder mission

• June 30, 2021: The 2020 Atlantic hurricane season was one of the most brutal on record, producing an unprecedented 30 named storms. What's more, a record-tying 10 of those storms were characterized as rapidly intensifying — some throttling up by 100 miles per hour in under two days. 8)

- To bring more data to forecasters and have a more consistent watch over Earth's tropical belt where these storms form, NASA has launched a test satellite, or pathfinder, ahead of a constellation of six weather satellites called TROPICS (Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats). Planned for launch in 2022, the TROPICS satellites will work together to provide near-hourly microwave observations of a storm's precipitation, temperature, and humidity – a revisit time for these measurements not currently possible with other satellites.

- "As a lifelong Floridian, I've seen firsthand the devastating impact that hurricanes can have on our communities. And as climate change is making hurricanes even stronger, it's more important than ever that NASA and our partners invest in missions like TROPICS to better track and understand extreme weather," said NASA Administrator Bill Nelson. "NASA's innovation is strengthening data models that help scientists improve storm forecasting and understand the factors that feed these monster storms. TROPICS will help to do just that and we look forward to next year's launch of the TROPICS satellite constellation."

Figure 13: When launched, the TROPICS satellites will work together to provide near-hourly microwave observations of a storm's precipitation, temperature, and humidity. The mission is expected to help scientists understand the factors driving tropical cyclone intensification and to improve forecasting models (video credit: NASA)

- "TROPICS is the beginning of a new era. This mission will be among the first to use a constellation of small satellites for these types of global, rapid-revisit views of tropical storms," said Scott Braun, the TROPICS project scientist and a research meteorologist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

- Since tropical cyclones and hurricanes can change rapidly as they travel across the ocean, the increased observations from the TROPICS satellites will not only advance the science of understanding storm intensity, they also may improve intensity forecasts.

- "The project holds great promise to boost NOAA's steady improvements in weather and hurricane forecasts by feeding new environmental data into our world-class numerical weather prediction models," said Frank Marks, director of the Hurricane Research Division of NOAA's Atlantic Oceanographic and Meteorological Laboratory. After all six satellites are launched and positioned in 2022, "this new constellation will provide high frequency temperature and humidity soundings as we seek to learn how hurricanes interact with the surrounding temperature and moisture environment—key data that could improve hurricane intensity forecasts."


Figure 14: The TROPICS Pathfinder satellite, pictured above, was launched on 30 June 2021 on the Transporter-2 mission of SpaceX from Cape Canaveral, Florida. The satellite body measures approximately 10 cm x 10 cm x 36 cm and is identical to the six additional satellites that will be launched in the constellation in 2022. The golden cube at the top is the microwave radiometer, which measures the precipitation, temperature, and humidity inside tropical storms (image credits: Blue Canyon Technologies)

- A critical step to preparing for the constellation is the launch of a pathfinder satellite, a seventh identical copy of the TROPICS smallsats, that will enable full testing of the technology, communication systems, data processing, and data flow to application users in advance of the constellation's launch. This will allow time for adjustments to the ground system and data products, helping ensure the success of the TROPICS mission.

- "The TROPICS Pathfinder satellite is similar to a screening before the opening night of a big show," said Nicholas Zorn, the Pathfinder program manager from MIT Lincoln Laboratory. "Its mission is a real-world, end-to-end test, from environmental verification through integration, launch, ground communications, commissioning, calibration, operations, and science data processing. Any areas for improvement identified along the way can be reinforced before the constellation launches."

- MIT Lincoln Laboratory's William Blackwell is the TROPICS principal investigator. Six years ago, he submitted TROPICS as a proposal to NASA's Earth Venture Instrument competition series and was awarded funding. The Earth Venture Instrument program calls for innovative, science-driven, cost-effective missions to solve pressing issues related to Earth science.

- Aboard each TROPICS small satellite is an instrument called a microwave radiometer, which detects temperature, moisture, and rainfall in the atmosphere. On current weather satellites, microwave radiometers are about the size of a washing machine. On TROPICS' small satellites the radiometers are about the size of a coffee mug.

- Microwave radiometers work by detecting the thermal radiation naturally emitted by oxygen and water vapor in the air. The TROPICS instrument measures these emissions via an antenna spinning at one end of the satellite. The antenna listens in at 12 microwave channels between 90 to 205 GHz, where the relevant emission signals are strongest. These channels capture signals at different heights throughout the lowest layer of the atmosphere, or troposphere, where most weather we experience occurs.

- By flying the TROPICS radiometers at lower altitude and detecting fewer channels than their larger counterparts, in the channels they do carry, the radiometers deliver comparable performance.

- Miniaturizing the microwave radiometer has been an incremental process over the last 10 years for Blackwell and his team, spurred by the invention of CubeSats, satellites the size of a loaf of bread that are often economical to launch. TROPICS builds on Blackwell and his team's 2018 success in launching the first microwave radiometer on a CubeSat to collect atmospheric profiling data. The instrument aboard the TROPICS' six satellites has been upgraded to provide improved sensitivity, resolution and reliability and will make more targeted and rapid weather observations.

- "These storms affect a lot of people, and we expect that with the increased observations over a single storm from TROPICS, we will be able to improve forecasts, which translates to helping people get to safety sooner, protect property, and overall enhance the national economy," Blackwell says, looking ahead to the full constellation launch next year. "It is amazing technology that we have proven out that allows us to maximize the science from the instrument's size factor. To pull this off has taken contributions of so many people."

- The TROPICS science team includes researchers from MIT Lincoln Laboratory and MIT Department of Aeronautics and Astronautics; NASA's Goddard Space Flight Center; NOAA Atlantic Oceanographic and Meteorological Laboratory; NOAA National Hurricane Center; NOAA National Environmental Satellite, Data, and Information Service; University of Miami; Colorado State University; Vanderbilt University; and University of Wisconsin. The University of Massachusetts Amherst, Texas A&M University and Tufts University contributed to the technology development. Maverick Space Systems provided integration services for the Pathfinder, which was launched from SpaceX's Transporter 2 mission. Astra Space Inc. is providing launch services for the constellation. NASA's Launch Services Program based at Kennedy Space Center procured and is managing the Tropics Pathfinder launch service.

PACE-1 (Payload Accelerator for CubeSat Endeavors)

NASA needs to ensure new technologies are sufficiently vetted to stand up to the extreme demands of the space environment before implementing them for an exploration mission. This vetting process, called technology maturation, is accomplished through repeated design, assembly, and testing cycles. Flight tests are key to this process, which culminates with a technology demonstration in space. 9)

PACE's goal is to mature technology payloads, from early-stage proof-of-concept models to flight qualification for an operational space mission, all while shortening technology testing timelines.

The PACE initiative, managed by NASA/Ames, supports flight demonstrations, facilitating suborbital and orbital launches for technology payloads. The initiative reduces the cost, risk, complexity, and/or time required to mature technology, lowering the barriers to development. Getting more technology payloads tested in flight more frequently helps researchers iterate their designs faster.

PACE uses a flexible approach to accommodate a wide range of projects to fly as many new technologies as possible, particularly early-stage, higher-risk innovations. A variety of flight platforms – independent, commercial, or NASA's ADP (Advanced Development Projects) avionics system platform – can host payloads on PACE flights.

The PACE-1 mission launched to low-Earth orbit aboard SpaceX's Transporter-2 mission. This will demonstrate the ADP technology. ADP experiments will test communications and navigation functions. The mission carries four payloads: Intrepid, a low-cost, lightweight gamma and neutron particle detector and spectrometer; ADP Optical Retroreflectors, an assembly of optical reflectors to assist in laser tracking; Stellar Exploration RFID Tag, an active modulating radio frequency reflector that improves the ability of space object tracking radars to detect and track small satellites; and the Naval Information Warfare Center Nanosatellite Tracking Experiment, a passive radar retro-reflector that improves the ability of space object tracking radars to detect and track small satellites.


Figure 15: Connor Nelson, PACE flight software lead at NASA's Ames Research Center in California's Silicon Valley, performs a visual inspection of the PACE-1 6U CubeSat during testing (image credit: NASA/Ames Research Center/Dominic Hart)

PACE-1 payloads

• The Intrepid payload is developed by Ames; Dayne Kemp is the principal investigator.

• The ADP Optical Retroreflectors payload is developed using commercially purchased optical retroreflectors by Ames: Jan Stupl is the principal investigator.

• Stellar Exploration RFID Tag payload is developed by Stellar Exploration Inc. in San Luis Obispo, California; David Troy is the principal investigator.

• Naval Information Warfare Center Nanosatellite Tracking Experiment payload is developed by the Naval Information Warfare Center in San Diego, California.; Shawn Kocis is the principal investigator.



Timeline of the spacecraft separation sequence from Falcon 9: 10)

• T+57:50: NASA's PACE-1 satellite separates

• T+57:57: Satellogic's ÑuSat 19 Earth observation satellite separates

• T+58:04: ICEYE radar observation satellite separates

• T+58:32: NASA's TROPICS Pathfinder CubeSat separates

• T+58:37: PlanetiQ's GNOMES 2 radio occultation satellite separates

• T+58:44: Tyvak-0173 nanosatellite separates

• T+59:47: ICEYE radar observation satellite separates

• T+1:00:00: Tyvak-0211 nanosatellite separates

• T+1:00:08: Loft Orbital's YAM-3 satellite separates

• T+1:00:18: TU Berlin's TUBIN microsatellite separates

• T+1:00:23: Umbra's first radar observation satellite separates

• T+1:00:33: D-Orbit's ION satellite carrier separates with six CubeSats

• T+1:01:50: Space Development Agency's LINCS 2 satellite separates

• T+1:02:16: Satellogic's ÑuSat 20 Earth observation satellite separates

• T+1:02:30: Satellogic's ÑuSat 21 Earth observation satellite separates

• T+1:02:40: Capella's Whitney radar observation satellite separates

• T+1:02:46: ICEYE radar observation satellite separates

• T+1:04:12: Space Development Agency's LINCS 1 satellite separates

• T+1:04:29: DARPA's Mandrake 2 Able satellite separates

• T+1:05:33: ICEYE radar observation satellite separates

• T+1:06:48: First batch of Swarm SpaceBEE satellites separate

• T+1:07:10: Second batch of Swarm SpaceBEE satellites separate

• T+1:07:17: NanoAvionics' D2/AtlaCom-1 satellite separates

• T+1:07:24: Spire's first Lemur 2 CubeSat separates

• T+1:07:47: Satellogic's ÑuSat 22 Earth observation satellite separates

• T+1:07:56: Loft Orbital's YAM-2 satellite separates

• T+1:09:51: Spire's second Lemur 2 CubeSat separates

• T+1:09:58: DARPA's Mandrake 2 Baker satellite separates

• T+1:21:10: Spaceflight's Sherpa FX2 separates to begin deploying smallsats

• T+1:21:14: Spaceflight's Sherpa LTE1 transfer vehicle separates

• T+1:27:35: Three Starlink satellites separate.

1) Jeff Foust, "SpaceX launches second dedicated rideshare mission," SpaceNews, 30 June 2021, URL:

2) "Launch Rewatch: Transporter-2 Mission," SpaceX, July 2021, URL:

3) Danny Lentz, "SpaceX successfully launches Transporter 2 mission with 88 satellites," NASA, 30 June 2021, URL:

4) ‘Fingerspitzengefühl' – a German term, literally "finger tips feeling"; meaning intuitive flair/instinct.

5) "Exolaunch to Send its Largest Mission of One Ton of Smallsats into Orbit via SpaceX's Transporter-2 Rideshare Mission," Exolaunch, June 2021, URL:

6) Jodi Sorensen, "Who's onboard SXRS-5 (SpaceX Transporter-2)?," Spaceflight, 11 May 2021, URL:

7) "Satellites launched to boost connectivity and create jobs," ESA Applications, 01 July 2021, URL:

8) Kylie Foy, Ellen Gray, "Pathfinder Satellite Paves Way for Constellation of Tropical-storm Observers," NASA Feature, 30 June 2021, URL:

9) "What is NASA's Payload Accelerator for CubeSat Endeavors Initiative?," NASA, 29 June 2021, URL:

10) Stephen Clark, "SpaceX rocket hauls 88 small satellites into polar orbit," Spaceflight Now, 30 June 2021, URL:

The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (

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