by WASHINGTON — The upcoming launch of a NASA Earth science instrument on a commercial communications satellite illustrates the promise, but also the problems, of hosted payloads.
A SpaceX Falcon 9 is scheduled to lift off at 12:30 p.m. Eastern Time on April 7 from Cape Canaveral, Fla., placing the Intelsat 40e satellite into geostationary transfer orbit. There is a 90% chance that the weather will be acceptable for launch on the 23rdrd of the year by SpaceX.
Intelsat 40e, built by Maxar, carries a NASA-hosted payload called Tropospheric Pollution Emission Monitoring (TEMPO). The instrument, produced by Ball Aerospace, is designed to measure concentrations of air pollutants such as nitrogen dioxide, ozone and formaldehyde across the continental United States as well as parts of Canada, Mexico and the Caribbean.
“GEO’s TEMPO will provide hourly air pollution data for the first time,” said Xiong Liu, TEMPO Deputy Principal Investigator at the Center for Astrophysics | Harvard & Smithsonian, on a call with reporters April 5. Spacecraft in low Earth orbit can only provide measurements once per day for a given area as they pass overhead, usually at the same time each day.
TEMPO will also provide this data at a much higher resolution: “down to the neighborhood scale,” said Karen St. Germain, director of NASA’s Earth Sciences Division.
Those involved in the project pointed out the benefits of flying TEMPO as a hosted payload rather than a standalone satellite. “The TEMPO program is truly a win-win solution for key entities involved,” said Aaron Abell, TEMPO Project Manager at Maxar. “This leverages unused capacity in Maxar’s legacy satellite design for government missions. This reduces the cost of accessing space for the government as well as the cost for Intelsat as they are compensated for supporting the TEMPO mission.
When NASA selected TEMPO for development in 2012, there was widespread enthusiasm in government and industry about hosted payloads. A steady stream of commercial GEO satellites, at the time averaging 20 to 25 per year, seemed to provide plenty of paths for communications, Earth observation, and other payloads.
However, few such payloads have flown. The US Air Force cleared a contract vehicle for hosted payload flight, called HoPS, to expire in 2019 due to a lack of military payloads seeking rides. At the same time, a sharp decline in the GEO communications satellite market reduced the supply of satellites that could accommodate payloads.
This latest issue affected a NASA project called GeoCarb, which the agency originally selected to fly as a payload hosted on a GEO satellite through SES Government Solutions. However, in February 2022, NASA announced that it would instead seek to fly GeoCarb on its own satellite after concluding that there were no satellites available that could host the payload for launch by the end of the day. of 2024. In November, NASA announced that it would cancel GeoCarb due to cost overruns.
“There haven’t been as many as originally anticipated,” Kevin Daugherty, TEMPO project manager at NASA’s Langley Research Center, acknowledged of the hosted payloads. “However, some of the things we have learned from TEMPO are how to work with our business partners and our business practices.”
One issue he and others involved with the project mentioned was aligning payload development schedules with those of the host satellites. “One of the biggest reasons some of these hosted payload opportunities don’t mature is schedule risk,” said Jean-Luc Froeliger, senior vice president of space systems at Intelsat. “For a commercial operator, timing is extremely important. A satellite must be built quickly. It must be launched and put into service as soon as possible.
Abell cited a “myriad of details” to find a host that includes the timeline as well as finding a satellite technically capable of hosting a payload and located in the correct part of geostationary orbit. “These are multiple factors that made TEMPO work,” he said, “but also complicate the process.”
TEMPO was able to mitigate the schedule risks associated with hosted payloads because the instrument was already built by the time NASA selected Maxar to host it in 2019. rate,” Daugherty said.
But TEMPO itself has been years behind schedule. When selected in 2012, NASA planned to launch it in 2017. Daugherty said technical issues in the instrument’s development caused an eight-month delay. The instrument was then stored for a year and a half to two years while NASA searched for a host for it. After a few solicitations resulted in no bids, NASA finally entered into a contract with Maxar and Intelsat. Development of the spacecraft has been delayed by covid-related issues, he added.
The instrument itself cost just over $90 million, he said. The overall cost of the mission is $210 million if we include the cost of integrating and hosting TEMPO on the satellite, as well as engineering and support management expenses.
Commissioning of TEMPO is expected to begin in late May or early June, once Intelsat 40e reaches geostationary orbit, with scientific observations beginning in October. The instrument has a primary mission of 20 months, but Daugherty said TEMPO is similar to another instrument also built by Ball on a South Korean satellite that has been operating for three years, suggesting TEMPO could also operate much longer.
