Spaceflight Insider

ULA rep: Atlas V will help Orbital ATK’s Cygnus get back in the game

Orbital Sciences Corporation Cygnus spacecraft NASA photo posted on SpaceFlight Insider

Orbital's Cygnus space, despite the loss of the Orb-3 mission last year, will fly this year - atop a United Launch Alliance Atlas V 401 rocket. Photo Credit: NASA

CAPE CANAVERAL, Fla — After the Oct. 29, 2014, loss of an Orbital Sciences Corporation Antares booster, the Cygnus spacecraft and the estimated 5,000 lbs (2,268 kg) of cargo it carried, one of the first questions many had asked was: “What will they do now?” The firm, based in Dulles, Virginia, was relying on its Antares launch vehicle, which had already traveled to the International Space Station (ISS) successfully three times and had flown four times overall to carry out missions to the outpost. Now the company would have to be swift on its feet and find another path to orbit.

With its booster on the sidelines as Orbital investigated the problem, it found a solution and implemented needed changes – how would it fulfill its obligations under the $1.9 billion Commercial Resupply Services contract? The answer lies in one of the most reliable rockets that is currently in service – United Launch Alliance’s Atlas V.

It was announced in Nov. 2014 that Orbital had tapped the Atlas to fly at least one mission in 2015 and the company is planning on stocking the Cygnus that will carry out this mission with 7718 lbs (3500 kg) of supplies to the space station. This is compared to 7,991 lbs (3,625 kg) that the three prior flights had successfully delivered to the orbiting laboratory.

United Launch Alliance Atlas V 401 rocket Cape Canaveral Air Force Station Space Launch Complex 41 SLC 41 NASA photo posted on SpaceFlight Insider

According to Thorpe, the 401 configuration of the Atlas V has more than enough thrust to ferry a fully-laden Cygnus to orbit. Photo Credit: NASA

ULA will use the 401 configuration of the Atlas V, the lightest capacity booster fielded by the aerospace firm based in Centennial, Colorado. The launch vehicle will launch from Cape Canaveral Air Force Station’s Space Launch Complex 41 (SLC-41) no-earlier-than (NET) the latter half of 2015.

Although the first four flights of Antares were, by and large, flawless – the fact that the rocket employed 40-year-old rocket engines was a subject of concern in aerospace circles. Originally dubbed the “NK-33” in the early 1970s by the Kuznetsov Design Bureau (in fact, the rocket’s very initials come from its chief designer – Nikolay Kuznetsov), these engines were originally intended for use on the Soviet Union’s massive N-1 Moon rocket.

The Atlas V booster has been used for all manner of missions, running the gamut from those carried out for the Department of Defense, planetary and science missions for NASA and the National Oceanic and Atmospheric Administration, and also commercial payloads – such as the Worldview-3 spacecraft launched on Aug. 13, 2014 – from Vandenberg Air Force Base located in California.

The flight of Cygnus on an Atlas V will certainly mark one of the more unique missions of 2015.

If everything goes according to plan, there will be only one flight of Cygnus on Atlas as the company is currently planning to return the Antares to flight in 2016. However, as the likely cause of the loss of Antares last October was either a turbopump failure in one of the two AJ26 rocket engines that Antares used in its first stage failing or debris within the engine itself, the company has tapped another Russian-made engine – the RD-181 – for use on Antares.


Since the loss of the Cygnus CRS Orb-3 in October of last year Orbital ATK has worked to return its Cygnus spacecraft to flight. Photo Credit: Joel Kowsky / NASA

SpaceFlight Insider works to bring you, the viewer, on the “inside” – whenever possible. As such, we sat down with ULA’s Vern Thorp to find out more about this mission – specifically about what differences there will be between a typical flight of an Atlas V, as opposed to the one that will carry Cygnus on the first part of its journey to the International Space Station.

SpaceFlight Insider: Thanks for chatting with us today Vernon. What does this mission mean for United Launch Alliance? How unique is it in terms of what your company does?

Thorp: “At a very, very top level it looks different because, you know, it’ll be a cargo mission, it’ll be our first one and there are some unique aspects in terms of processing to get us ready for it.  Once we dug into the details and started working with Orbital, talking to them about what it would take to fly this mission, it turns out that it looks very ‘standard’ to us.

“When we fly the typical NASA science missions, oftentimes, they have to buy not only a standard launch service but they have all kinds of mission-unique requirements that we have to accommodate. Some examples would be, say, for instance, the Pluto New Horizons and the Mars Science Lab Curiosity missions we have to put in these gigantic doors in the payload fairing (PLF) so people can mount nuclear power sources and [there are] all sorts of special air conditioning and sometimes even fluid systems requirements.”

SpaceFlight Insider: So the size of Cygnus did not cause any issues or drastic changes?

Thorp: “For the Cygnus cargo module, although it’s big and it looks very different from most of the spacecraft that we fly, it’s actually very compatible with our standard launch service,” Thorpe said. “The primary technical difference that we had to accommodate – was the mechanical interface. Cygnus uses one of the standard separation systems and interface ring sets that RUAG (the manufacturer of the payload fairings that ULA utilizes) manufactures in Sweden. But it is an interface that we have not flown before, so we are developing a new payload adapter to be compatible with that wider interface ring. Aside from that? There are very few, what we call mission-unique services required. In fact, it’s pretty much on the low end compared to many of the NASA missions that we fly.”

NASA_atlas_v_mms-michael_howard SpaceFlight Insider

Unlike the Atlas V that carried out the launch of NASA’s Magnetospheric Multiscale Mission on March 12, the Atlas that will be used to send the Cygnus CRS Orb-4 to the ISS will not utilize any solid rocket motors. Photo Credit: Mike Howard / SpaceFlight Insider

SpaceFlight Insider: Are there any difficulties in sending Cygnus to the ISS?

Thorp: “For this mission, we will be flying to low-Earth orbit and, in terms of our experience base, we’ve flown a lot of missions to low-Earth orbit, we fly them frequently, but we usually fly them from Vandenberg. Many of the NASA science missions, including the SMAP mission that we recently launched on a Delta II, went into a low-Earth orbit; I think it was a 370 nautical mile, almost circular orbit, and we do that a lot out of Vandenberg,” Thorpe said. “So this will be a bit different in that we are flying out of the Cape. Launches that we conduct from the Cape are usually headed to a geosynchronous transfer orbit or, sometimes, we take them all the way out to GEO or, for the NASA interplanetary missions, we take them to [an] escape [trajectory]. So, this will be the first time in a long time, the first time in my experience certainly, that we have flown a low-Earth orbit mission out of Cape Canaveral. Obviously, that is what is required to place Cygnus in an orbit that will allow it to travel to the International Space Station.”

SpaceFlight Insider: What will Atlas/Centaur do in terms of getting Cygnus’ cargo to the ISS?

Thorp: “What we will do is take the cargo module to a little bit below the space station orbit and then after we separate them (from Atlas’ Centaur upper stage) they will do some additional maneuvering to properly phase with the station and, eventually, get up to their exact orbit.”

SpaceFlight Insider: The outward appearance of Cygnus lends to the impression that the 401 configuration of Atlas might not have the upmass capability required for such a flight; obviously, this is an inaccurate assessment?

Thorp: “We have plenty of performance on the 401 configuration of the Atlas V to be able to do this mission. You know, if you compare the performance level of the 401 to the Antares that they were using when they launch out of Wallops, Atlas actually has more capability – it’s a bigger vehicle. So, even though we are launching out of a different location, we have plenty of performance to match what Orbital’s Antares is able to do; in fact, we’re able to offer a little more performance.

“One of the things that Orbital is going to do is to investigate how they can take advantage of that extra capability and maybe load a little extra cargo on board. So the goal, and it is certainly technically feasible, is to have significantly greater amount of cargo when they fly on top of an Atlas, to help them meet their overall commitment to NASA. In fact, I think when Orbital put out their first press release on this last year, they even said that they should with one or two Atlas launches – they should be able to meet their commitment on total cargo taken to the station with one less launch than they had originally envisioned.”

SpaceFlight Insider: How many flights does Orbital currently have with ULA?

Thorp: “What we have right now is the capability to offer them a couple of rides. One this year and one next year, if they need it. What Orbital will do is, they will assess… their ability to get Antares up and operational and – if they conclude that they can do that in a timely manner and go be able to meet all of their requirements with just a single Atlas launch – there are provisions within the contract that allow them to do that. If they decide that they want the second Atlas launch? There are provisions within the contract that accommodate that as well. I think the way that they characterized it in their press releases was that they got one launch with an option for one more and that’s a fair way to categorize it.

“The first launch will be late this year, with a second one possible – if they choose to go forward with it – would be in 2016. They are trying to maintain some flexibility to be able to deal with whatever they find as they try to get Antares back on line.”

An Atlas V 421 with NASA's Magnetospheric Multiscale Mission launches from Cape Canaveral Air Force Station Space Launch Complex 41 SLC-41 photo credit Mike Deep SpaceFlight Insider

The launch of Cygnus CRS Orb-4 is currently slated to take place in the fourth quarter of this year. Photo Credit: Mike Deep / SpaceFlight Insider

SpaceFlight Insider: We were surprised that ULA tapped the four instead of the five meter fairing to carry out this mission.

Thorp: “Keep in mind that we have three different lengths of that four-meter fairing and Cygnus definitely pushed us to the longest version. So, for our four meter fairing, we have three different configurations; the standard one, we call the ‘LPF’ – that acronym goes back into ancient history is used to stand for ‘large payload fairing’ that was used back to when we were flying the 11 foot diameter as well as the 14 foot diameter. That was a standard size; then, in the mid-90s, to accommodate the EOS-Terra mission for NASA which we launched in 1999, we actually implemented a three-foot stretch to the cylindrical section of the fairing and we called that our ‘EPF’ or extended payload fairing.

“There was another mission, one I believe for the DoD (Department of Defense) that required even more volume and they inserted another three foot plug. There’s like a three-foot barrel section, if you will. We added one to the EPF and then we added another one, which created our longest version, which we called the ‘XEPF’ and that’s like the extra-long payload fairing. That third version, that longest version that we have, the Cygnus configuration will… absolutely require that. It is a tight fit – definitely. You know, we’ve got a static envelope that, if a payload stays within that envelope, then, once you account for all of the vibration movement that happens during flight, you ought to be okay and one of the first things we did when we began working with Orbital was to verify that it could fit in that XEPF, and it’s a tight fit – but it does.”

SpaceFlight Insider: Vern, the big question – when will we see this launch? 

Thorp: “We’re notionally out in the fourth quarter of this year and I don’t know if I can talk about specific dates, it is… the only thing that is constant about launch schedules is that they change all the time. But we’re looking at the middle of the fourth quarter right now and we’re protecting the ability to go earlier if we need to, so we are prepared to launch anytime in the fourth quarter of this year.

“The actual date that we pick will depend on how the other launches move around and it will also depend on the arriving and departing vehicle schedule up at the space station, because it’s obvious that we have to coordinate with that and I suspect that the schedule with the folks down at Johnson Space Center manage all of the activities at the station and when they can accommodate an arriving vehicle – that will probably be one of the primary determinations of what the launch date is when we get there and I’m guessing we’ll have a really good handle on that six months in advance.”

SpaceFlight Insider: Vern, thanks for taking the time out of your busy schedule to talk with us today.

Thorp: “My pleasure!”

Orbital ATK Cygnus spacecraft attached to Canadarm 2 on board the International Space Station NASA photo posted on SpaceFlight Insider

Thorpe stated that, by and large, launching Cygnus to the ISS should pose little problem for ULA. Photo Credit: NASA


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Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

Too bad ULA doesn’t produce enough Delta IV mediums to make them compatible cost wise. I would’ve loved to see Cygnus launch on a Delta IV.

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