The latest version of the ESPA ring arrays experiments but also more advanced operational smallsats

A ring-shaped satellite carrier the U.S. Air Force developed a decade ago to arrange experiments has evolved into a reliable asset to get small national security payloads to geosynchronous Earth orbit. 

The ESPA ring which is short for Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter, was created to fill unused capacity on national security space rockets. The newest version of the ring designed by Northrop Grumman, the Long Duration Propulsive ESPA or LDPE, deploys experiments but also more advanced operational smallsats.

Each ring has six ports that can accommodate 320 kilograms of payload mass per port.

“LDPE provides added propulsion, power, and avionics subsystems enabling operations as a fully functional satellite,” Space Systems Command program manager Lt. Col. Michael Rupp, said in a news release.

Under a contract with U.S. Space Systems Command, Northrop Grumman built three LDPE rings for national security missions. One launched in December 2021, the second in November 2022 and the third one will fly on a SpaceX Falcon Heavy in the upcoming USSF-67 mission. A more advanced version of the ring is in the works under a July 2022 $22 million contract.

Space Systems Command said all payloads on LDPE-1 and LDPE-2 were successfully deployed to geostationary orbits. 

The original ESPA ring started as a joint development by the Air Force Research Laboratory and Orbital Sciences back in 2012, said Troy Brashear, Northrop Grumman vice president of national security systems. Orbital Sciences was later acquired by Northrop Grumman.

Military customers are seeing the utility of the ESPA ring as a much more affordable option than dedicated launches, and the rings are flexible enough that payloads can be swapped at the 11th hour, Brashear told SpaceNews

“An interesting part of this satellite program is the ability to make changes on the fly,” he said. That is not possible with most space missions where the payloads are designed for specific interfaces and substitutions are difficult to make. “On LDPE we’ve been able to show that payloads on any of the six ports can be swapped out as late as at the launch site.”

Northrop Grumman manufactures the ESPA satellites in Gilbert, Arizona. After being shipped to Cape Canaveral, individual payloads in recent missions were changed out right before launch, he said. “And it provided a ton of flexibility to the customer.” 

A sort of resilience

Brashear said the ability to add a new payload to the mission on short notice is increasingly important as a form of resilience, giving the Space Force options to deploy experiments or operational satellites in response to emerging needs. 

“The foreign threat environment is changing pretty fast. And for our customers, speed and agility to stay ahead of those challenges is paramount,” he said. “This program is providing that sort of resilient architecture to put things into orbit faster, and cheaper since it’s a very small satellite structure, utilizing empty space on a ride that would go unused.”

The LDPE satellites fly to geostationary orbit on big rockets that typically carry a large primary payload and the ring as a secondary payload. When it reaches orbit, the LDPE is released from the second stage. Once the ring is deployed, the individual payloads can stay attached to the platform permanently or can be dispensed as independent satellites, go off and do their own missions.

“The U.S. government’s investment over the last 10 years in these ESPA products has just timed up very nicely with the threat environment,” he said. “If these investments hadn’t been made 10 years ago, we wouldn’t have this freight train to space where we can take six payloads up in a cost-effective manner.”

Another benefit of these rings is that they are interchangeable with any of the national security space rockets the Space Force uses, which are operated by United Launch Alliance and SpaceX. LDPE have launched on ULA’s Atlas 5 and on SpaceX Falcon Heavy. “There are obviously different loads and dynamics and testing,” said Brashear. “But both ULA and SpaceX have been fantastic to work with.”

Lockheed Martin is set to buy buses from Terran Orbital for the Space Development Agency’s Transport Layer.

An announcement coming from Terran Orbital, is that it has completed delivery of 10 satellite buses ordered by Lockheed Martin for the Space Development Agency’s mesh network in low Earth orbit.

The first satellite bus was delivered in May. 

Lockheed Martin won a $187.5 million contract from the Space Development Agency (SDA) in August 2020, to produce 10 communications satellites for the Transport Layer Tranche 0. 

The Tranche 0 constellation will provide secure high-bandwidth, low-latency data links for military users.

Terran Orbital, based in Boca Raton, Florida, in October announced Lockheed Martin made a $100 million investment in the company that will be used to expand Terran Orbital’s satellite manufacturing facilities in Irvine, California.

Lockheed Martin also selected Terran Orbital as its satellite bus supplier for the Transport Layer Tranche 1, a much larger constellation of satellites made by Lockheed Martin, Northrop Grumman and York Space.

Lockheed Martin’s Tranche 0 satellites are projected to launch in June.

The expansion of manufacturing capacity in Irvine is intended to help meet a 2024 deadline to deliver 42 buses for SDA’s Tranche 1 under a $700 million contract. 

Terran Orbital CEO Marc Bell said the delivery of Tranche 0 satellites coincides with the company’s “shift from lower quantity, mission-unique satellites to robust production.”

This fall Terran Orbital announced it would abandon plans to build a constellation of 96 synthetic aperture radar satellites, called PredaSAR, in order to focus on the production of satellites for U.S. defense and national security customers. The company also formed a new business unit that will produce electro-optical imaging satellites.

There has been proposed constellation of six CubeSats to map lightning.

Cubespark CubeSats, equipped with high-resolution optical imagers and VHF sensors, would “map not only the flash locations, but map the full structure of it deep within convective clouds,” Jackson Remington of the Universities Space Research Association said Jan. 9 at the American Meteorological Society conference here.

Cubespark is designed to measure the global distribution of lightning, help explain the relationship between lightning and severe weather, and monitor lightning-produced nitrogen oxides, which have an impact on air quality.

The data currently comes from a variety of sources including terrestrial sensors and the Geostationary Lightning Mappers on the National Oceanic and Atmospheric Administration’s Geostationary Operational Environmental Satellite-R series. In low Earth orbit, a Lightning Image Sensor (LIS) designed by scientists at the University of Alabama, Huntsville, and manufactured at NASA Marshall has been making observations since it was installed on the International Space Station in 2017.

“It’s important to point out that low-Earth orbit observations are at risk,” Remington said.

LIS is scheduled to stop gathering data from the space station later this year “and there’s no planned successor of a day-night lightning imager” in low-Earth orbit, Remington said. “So, we really need to get these up there,” he added.

In simulations, the Cubespark constellation was able to pinpoint the location of lightning to within one to two kilometers over a 300- to 600-kilometer swath from the tropics to high latitudes, Remington said.

NASA’s Earth Science Technology Office is supporting the Cubespark concept through its Instrument Incubator Program.

The space station offers an excellent vantage point to scientists studying TLEs. At about 250 miles up, it is much closer to these phenomena than a geosynchronous satellite. Further, the stations’ orbit allows for coverage of storms worldwide.

All this allows LIS and ASIM to produce a unique space-based dataset of thunderstorms and their effects, which in turn helps support other observational instruments. LIS for example has been used to calibrate instruments and verify data for the Geostationary Lightning Mapper on NASA and NOAA’s GOES satellites, and will also support the lightning imager on the European satellite, Meteosat Third Generation. This support helps make the data produced by these sensors the highest quality for serving the public.

From the space station, LIS can provide lightning data in near-realtime for the benefit of those on Earth. It can report lightning nearing dry areas of forests prone to wildfires. It’s integrated into the NOAA Aviation Weather Center’s operations, which provides weather forecasts and warnings to the US and international aviation and maritime communities. And, over time, it can map data points to help scientists observe changes to our climate over broad tracts of land and sea.

In short, studying lightning and its effects both below and above the clouds can have a big impact on how we view our planet.

Samsung has entered into a service provider agreement with Iridium to connect its satellites to the new upcoming smartphones.

The U.S.-based satellite operator said it is due to be paid royalties, development and network usage fees from the deal in a Dec. 30 regulatory filing that provided no financial details or timings.

“To protect each company’s investment in this newly developed technology, the overall arrangements include substantial recoupment payments from each company for commercializing a similar capability,” Iridium said.

The announcement comes after Iridium said in July that it had signed a development contract with a company to enable its satellite technology in smartphones. 

Iridium said both agreements are still contingent upon successfully developing the technology.

Samsung plans to use Iridium’s constellation to bring satellite connectivity to its range of Galaxy S23 range of smartphones this year, South Korean media publication ETNews reported Nov. 24.

Unlike the direct-to-smartphone service Apple launched Nov. 15 with Iridium’s rival Globalstar, ETNews said Samsung’s service would extend beyond basic SOS messaging to enable texts and low-resolution images to be sent outside terrestrial networks. 

While Iridium and South Korea-based Samsung have declined to comment on the ETNews report, Lee Seung-gwan, a senior executive at Samsung Electronics’ communications team, said a “smartphone-satellite connection is something we should pursue, obviously.”

The partnership would make sense for Iridium following Apple’s Globalstar tie-up, according to William Blair analyst Louie DiPalma, who expects the Galaxy S23 line-up to be released in February.

Globalstar’s willingness to allocate 85% of its satellite network to Apple helped seal its deal with the company behind one of the world’s most successful smartphones. 

But that level of commitment was not feasible for Iridium, DiPalma said in a note to investors Nov. 25, because thousands of blue chip customers including the U.S. Department of Defense currently rely on its network.

Even still, Iridium’s $3 billion 66-strong constellation is “considered significantly more advanced” than Globalstar’s network of 24 satellites, he said.

“In our view, the Iridium smartphone functionality will be more expansive than the Apple-GlobalStar iPhone14 partnership,” he added.

During Iridium’s latest earnings call Oct. 20, CEO Matt Desch hinted that “you can do a lot more than just push an emergency button” with a smartphone connected to a satellite. 

Apple has kept its future direct-to-smartphone plans close to its chest as it invests $450 million to upgrade Globalstar’s network.

Meanwhile, other established and startup satellite companies are preparing to offer more than just basic emergency messaging when they launch their direct-to-smartphone services in the coming years.

Texas-based AST SpaceMobile is preparing to start deploying operational satellites from late 2023 to bring 5G connectivity directly to smartphones.

Samsung Next, Samsung’s investment arm, was an early investor in AST SpaceMobile.

DiPalma expects an Iridium partnership with Samsung would contribute $20 million in revenues in its first year, although “that estimate may be conservative.”