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Rideshare Opportunities

This chapter briefly summarizes current and past experiences with rideshare opportunities, setting the stage for a NASA HPD agile rideshare program.

DEFINITION OF REPORT TERMS

In this report, the term “rideshare opportunities” is used to refer to all types of launch vehicles that might carry secondary payloads in addition to the primary payload. Rideshare opportunities may vary in terms of the locations to which they deploy payloads, from near-Earth to lunar orbits and beyond. These potentially include suborbital flights at very low altitudes (<200 km); low Earth orbits (LEOs) at both low and high inclination; medium-altitude Earth orbits (e.g., GPS); high-altitude Earth orbits; L1, L4, and L5 or out-of-the-ecliptic vantage points in the heliosphere; lunar and planetary missions; and interplanetary rideshare opportunities.

Secondary payloads include individual instruments or one or more spacecraft. This report defines a “host platform” as any structure that the secondary payload interfaces with to utilize a rideshare opportunity. Note that a secondary payload may be a “ridealong” or a “free-flyer.” Ridealong refers to an instrument that remains on and interfaces directly with a primary payload. A free-flyer is an autonomous spacecraft or group of autonomous spacecraft with or without propulsion. Propulsion¹ opens up many options for orbits beyond the orbit of the primary payload (see the section “Secondary Payloads with Propulsive Capability,” in Chapter 4).

This report refers to a “constellation” as a mission consisting of multiple spacecraft in specified orbits. Variations of constellations include swarms (closely spaced formation flying spacecraft), clusters (irregularly spaced and less organized groups of spacecraft), global constellations (spacecraft that are evenly spread globally), and ad hoc or grassroots constellations (combinations of heterogeneous spacecraft or sensors).

Throughout this report, “agile rideshare program” is shorthand for a program characterized by agile responses to short-notice rideshare opportunities. The desired response time may vary depending on the type of measurement and the nature of the opportunity. However, the target time scale would be substantially faster than typical NASA mission development times of multiple years.

EXAMPLES OF PAST AND CURRENT RIDESHARE OPPORTUNITIES

The existence of rideshare opportunities for both free-flyer and ridealong secondary payloads is not a new phenomenon, as satellites both within NASA and across agencies have been used in this manner for

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¹ NASA, “State of the Art Spacecraft Technology,” updated March 19, 2020, https://sst-soa.arc.nasa.gov/04propulsion.

some time. Examples of free-flyers include the Jason,² Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED),³ and most recently the Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites (TRACERS) Small Explorers mission selected to share a launch with the Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission.⁴ Examples of ridealongs include NASA’s Global-scale Observations of the Limb and Disk (GOLD) mission of opportunity on a commercial communications satellite,⁵ Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) on Department of Defense (DoD) satellites, and also secondary payloads hosted on the Iridium NEXT constellation satellites, including Federal Aviation Administration (FAA) aircraft tracking transmitter/receivers. In addition, sensors integrated in satellites for avionics purposes can occasionally provide measurements of scientific interest. NSF’s Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) geospace facility uses avionics magnetometers on the Iridium satellites to achieve effective secondary payload capability without requiring hardware accommodation, although flight software modification and implementation was necessary to obtain data not originally intended for storage and downlink.

Rideshare opportunities and agile access to space are not new concepts. For example, the Space Experiments Review Board (SERB)⁶ has been providing launch opportunities as part of the DoD Space Test Program (STP) for decades. NASA’s Sounding Rocket Program⁷ provides, among other services, short-notice opportunities for calibration underflights and now supports CubeSat launches. The recent growth in the number of CubeSats and small satellites has required additional launch support, such as that provided by NASA’s CubeSat Launch Initiative (CSLI).⁸ Other initiatives include the NSF CubeSat-Based Science Missions for Geospace and Atmospheric Research program, the Air Force Office of Scientific Research (AFOSR) University Nanosatellite Program,⁹ and NASA’s Space Launch System (SLS)¹⁰ demonstration test flight that facilitated the first Small Innovative Missions for Planetary Exploration (SIMPLEx) developments.

Small satellite technologies have advanced substantially in recent years, in part through the Small Spacecraft Technology Program and the Technology Demonstration Missions (TDM) programs of NASA’s Space Technology Mission Directorate (STMD), as well as technological advances from commercial small spacecraft system providers. In addition, the opportunity space for constellation missions was recently expanded by the reduction of the mass and volume ofF free-flyer payloads, as achieved by the international small satellite collaboration COSMIC-2.¹¹ The international Committee on Space Research (COSPAR) 2019 article “Small Satellites for Space Science: A COSPAR Scientific

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² Jet Propulsion Laboratory, California Institute of Technology, “Mission to Earth: Jason-3,” https://www.jpl.nasa.gov/missions/jason-3/, accessed April 6, 2020.

³ NASA, “TIMED,” updated August 3, 2017, https://www.nasa.gov/timed.

⁴ NASA, “GOLD: Global-scale Observations of the Limb and Disk,” https://www.nasa.gov/subject/13163/goldglobalscale-observations-of-the-limb-and-disk, accessed April 6, 2020.

⁵ Spaceflight Now, “Ariane 5 Deploys Two Telecom Satellites in Orbit Despite Telemetry Loss,” January 26, 2018, https://spaceflightnow.com/2018/01/26/ariane-5-va241-status-1/.

⁶ U.S. Air Force Kirtland Airforce Base, “Space Test Program,” January 25, 2007, https://www.kirtland.af.mil/About-Us/Fact-Sheets/Display/Article/826059/space-test-program/.

⁷ NASA, “Sounding Rockets,” updated August 3, 2017, https://www.nasa.gov/mission_pages/soundingrockets/index.html.

⁸ NASA, “CubeSat Launch Initiative,” updated March 4, 2020, https://www.nasa.gov/content/about-cubesatlaunch-initiative.

⁹ NSF, “CubeSat-Based Science Missions for Geospace and Atmospheric Research,” https://www.nsf.gov/funding/pgm_summ.jsp?pims_id=503172, accessed April 6, 2020.

¹⁰ NASA, “NASA Explores with Space Launch System,” updated April 3, 2020, https://www.nasa.gov/exploration/systems/sls/index.html.

¹¹ UCAR Community Programs, “FORMOSAT-7/COSMIC-2 (COSMIC-2),” updated April 6, 2020, https://www.cosmic.ucar.edu/what-we-do/cosmic-2/.

Roadmap”¹² illustrates international interest and contributions to advancing science through rideshare opportunities. The European Space Agency (ESA) is also implementing a distributed space weather sensor system utilizing secondary payloads for space weather monitoring.¹³

Last, ESPA ring development, as employed for the DoD Demonstration and Science Experiments (DSX) satellite¹⁴ and planned for NASA’s IMAP mission, extends the current opportunity space for launch rideshare opportunities from CubeSats to small satellites up to ~100 kg mass. NASA is currently evaluating missions of opportunity for science and technology demonstrations to ride along on the IMAP ESPA ring, as well as providing a ride for NOAA’s Space Weather Follow-On (SWFO) mission.¹⁵

Finding: NASA science currently benefits from a range of commercial and agency rideshare opportunities.

FUTURE LANDSCAPE OF RIDESHARE OPPORTUNITIES

In the past, all missions and payloads to solve specific problems were proposed and competed long in advance of the desired launch date. With recent increases in launch opportunities, the ability to provide instruments or small satellites that can be quickly prepared for launch has become desirable. The challenge to take advantage of these opportunities is that the development time frame for commercial missions is often shorter than the normal procurement cycle for civilian spaceflight. For example, Iridium NEXT deployed 75 satellites over eight launches from January 2017 through January 2019, with extra ridealong capacity made available to accommodate secondary science payloads. The required response time to accommodate the launch schedule was too short for the normal NASA proposal or procurement process, which is on the order of 18 months from announcement of opportunity to selection, followed by the months to years to build and test the payload. For this reason, NASA was not able to take advantage of the Iridium opportunity. Relatedly, a concept to incorporate dual-frequency GPS on Iridium NEXT, called GeoScan, was conceived for NSF sponsorship, but the timeline of several years for a midscale NSF project (including engagement with the science community to build consensus) also proved to be too long.

The mismatch between rideshare opportunity schedules and procurement timelines is likely to preclude participation in future opportunities and will be exacerbated as the number of opportunities grows. Since June 2010, SpaceX has successfully launched 73 Falcon 9 family missions, 19 of which were multipayload missions, and 8 of which were the deployments of the 75 Iridium NEXT satellites. The recent launch of Starlink satellites¹⁶ and the expansion of Rocket Lab’s small satellite launch services¹⁷

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¹² R.M. Millan, R. von Steiger, M. Ariel, S. Bartalev, M. Borgeaud, S. Campagnola, and J.C. Castillo-Rogez, et al., Small satellites for space science: A COSPAR scientific roadmap, Advances in Space Research 64(18):1466-1517, 2019, https://doi.org/10.1016/j.asr.2019.07.035.

¹³ S. Kraft, A. Lupi, and J.-P. Luntama, ESA’s distributed space weather sensor system (D3S) utilizing hosted payloads for operational space weather monitoring, Acta Astronautica 156:157, 2018, doi: 10.1016/j.actaastro.2018.01.020.

¹⁴ J. Schoenberg, G. Ginet, B. Dichter, M. Xapsos, A. Adler, M. Scherbarth, and D. Smith, “The Demonstration and Science Experiments (DSX): A Fundamental Science Research Mission Advancing Technologies That Enable MEO Spaceflight,” European Space Agency (Special Publication), 2006, https://lwsset.gsfc.nasa.gov/documents/DSX_paper.pdf.

¹⁵ National Oceanic and Atmospheric Association (NOAA) Office of Projects, Planning, and Analysis (OPPA), “Space Weather Follow-On,” https://www.nesdis.noaa.gov/OPPA/swfo.php, accessed April 6, 2020.

¹⁶ Space News, “SpaceX Submits Paperwork for 30,000 More Starlink Satellites,” updated October 15, 2019, https://spacenews.com/spacex-submits-paperwork-for-30000-more-starlink-satellites/.

¹⁷ Rocket Lab, “Rocket Lab Opens Launch Complex 2, Confirms U.S. Air Force Payload as First Electron Mission from U.S. Soil,” https://www.rocketlabusa.com/news/updates/rocket-lab-opens-launch-complex-2confirms-u-s-air-force-payload-as-first-electron-mission-from-u-s-soil/, accessed April 6, 2020.

illustrate the likelihood that such launch capabilities will expand greatly, particularly for geosynchronous orbits (GEO) and LEO. As a cautionary note, the impact of increased satellite traffic on views of the night sky and space traffic management cannot be ignored.¹⁸ Serendipitous opportunities may arise at other orbits, including deep space or planetary destinations that would require quick response.

NASA’s Shuttle Small Payloads Project Office (SSPPO) was developed to deal with a similar situation when the NASA Space Shuttle Program provided an abundance of launch capacity that was being underutilized. This office worked with the shuttle flight planning board to manifest, coordinate, and facilitate approved experiments to fly on the numerous space shuttle flights, making use of excess space and lift capacity. Lessons learned point to the importance of building a central organization, setting standards, and developing a flexible, broad-based program.¹⁹

Finding: The future cadence of rideshare launch opportunities will increase, presenting a new organizational challenge for NASA HPD to maximize the potential for scientific return.

Taken together, these findings support the committee’s conclusion, as follows:

Conclusion: Short-notice rideshare opportunities are likely to arise more frequently on a variety of host platforms and at a variety of orbits, motivating a program dedicated to an agile response to these opportunities.

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¹⁸ J. O’Callaghan, “The Risky Rush for Mega Constellations,” Scientific American, October 31, 2019, https://www.scientificamerican.com/article/the-risky-rush-for-mega-constellations/; American Astronomical Society, “AAS Issues Position Statement on Satellite Constellations,” June 10, 2019, https://aas.org/press/aas-issuesposition-statement-satellite-constellations.

¹⁹ G. Daelemans and S. Christe, “The NASA Small Payloads Project Office—Solving the Problem of Excess Launch Capacity in the Shuttle Era,” white paper submitted to the Committee on Solar and Space Physics, 2019.