SLS Waiting For Primary Roles:

As outlined in previous articles on this site, NASA managers are continuing with their efforts to refine the Design Reference Mission (DRM) roadmap for the Agency’s new flagship launch vehicle.

While that process continues, clues to the roadmap’s foundations can be found in NASA documentation, such as the SLS Concept Of Operations (Con Ops) presentation (available on L2 – Link to Presentation), which provides a detailed overview of the large number of the DRMs under consideration.

*Click here for the list of SLS Con Ops Articles*

As to when the process will be complete, a lot will depend on information relating to budget support for NASA, specifically the SLS and Orion programs.

In turn, SLS managers need to present a roadmap and a schedule which is far removed from the “worst case” scenario, one which sees SLS involved in a widely-spaced opening salvo of missions, before increasing to a flight rate of just one mission per year in the 2020s – an unacceptably low flight rate in most people’s eyes.

NASA managers are fully aware of this, with the SLS team already looking as far ahead as FY14 in their recent manifest meeting, based mainly around the previously reported wish to halve the gap between SLS-1 in 2017 and SLS-2.

With the “worst case” manifest showing SLS-2 would launch in 2021 – otherwise known as the first crewed mission for SLS and Orion – it is understood that if this mission cannot be advanced to 2019, an alternative option would be to launch SLS on a cargo mission in that year.

It has not yet been determined what type of cargo would fly on the SLS – a Block I (70mt) HLV – in such a schedule scenario.

Other Roles For SLS:

SLS’ design was technically selected ahead of knowing what specific missions it would be conducting. While it has been argued the payloads should determine the design of the launch vehicle, its upmass capabilities and fairing size options at least provide some guidelines to its future passengers.

As noted in the SLS Con Ops presentation, flexibility is inherent with a vehicle that will debut as a 70mt deriviative, prior to growing to 100mt (Block IA) and later to a 130mt (Block II). The aim is to evolve the SLS to its full capability in time for potential missions to Mars.

“The SLS changes the paradigm of what can be launched, because its launch performance is far greater than that of any current vehicle. In addition, its dramatically larger launch fairing enables launching large, multi-element systems, greater science instrument mass fraction, larger electrical power supplies, and more mass for shielding and lower-complexity engineering solutions,” noted the SLS Con Ops presentation.

“This translates into an earlier return on science, a reduction in mission times, and greater flexibility for extended science missions.”

Notable additions to the DRM section of the presentation are roles for the SLS which are separate from those which involve NASA’s future exploration aspirations.

Secondary Payloads – SpaceX and SLS:

One of these additional roles relates to “Secondary Payloads” – in other words, spacecraft – usually much smaller than the primary passenger – that could potentially hitch a ride uphill with the SLS.

The subject of secondary payloads became an important subject for SpaceX recently, as the Californian company noted its agreement to launch 18 ORBCOMM Generation 2 (OG2) satellites would be carried out – as secondary payloads – during Falcon 9 launches.

Originally, the delivery of the second-generation satellites into Low Earth Orbit (LEO) was set to be carried out on the Falcon 1e launch vehicle.

SpaceX noted the switch to Falcon 9 was made to further maximize the cost-effectiveness of their COTS/CRS missions, by including these additional payloads as passengers on the Falcon 9′s second stage, allowing them to be deployed after the Dragon spacecraft separates from the launch vehicle.

When SpaceX were asked if there was still a future role for Falcon 1/1e following this switch, the company’s communications director Kirstin Brost Grantham told NASASpaceflight.com: “Current plans are for small payloads to be served by flights on the Falcon 9, utilizing excess capacity. This is a very cost effective solution for small satellite launch needs.”

With a number of the OG2 satellites set to fly with the next Falcon 9 – the combined COTS 2 and 3 Demo mission – NASA teams used their experienced Monte Carlo analysis methods to review the deployment of the satellites, so as to ensure they did not hold an impact risk to the International Space Station (ISS).

For SLS, the Con Ops presentation noted the potential use of an Encapsulated Secondary Payload Adapter (ESPA) ring to allow for additional passengers to ride with the monster rocket.

“The SLS will pursue opportunities to fly secondary payloads in conjunction with primary missions. These services can be provided by the Science Mission Directorate (SMD), allowing deployment of these payloads along the SLS trajectory. An ESPA ring may be flown to accommodate this class of payloads.”

For SLS/HLV Articles, click here: http://www.nasaspaceflight.com/tag/hlv/

SLS DoD Missions:

In a reminder of the Space Shuttle’s past, SLS managers are also eyeing up the possibility of launching military payloads on the HLV.

Currently, most DoD spacecraft are launch by EELVs (Evolved Expendable Launch Vehicle), such as the Atlas V or the Delta IV vehicles, under the control of the United Launch Alliance (ULA). However, for a period during the early years of the Shuttle’s lifetime, the orbiter’s role with classified DoD payloads was commonplace.

During the Shuttle era, the orbiters enjoyed both “dedicated” DoD missions – beginning with Columbia’s STS-4 flight – and “civilian” missions that carried, or deployed, DoD payloads. The last dedicated DoD mission was in 1992 with Discovery during STS-53, while the last “civilian” mission with a DoD payload was in 2000, during Endeavour’s STS-99′s mission.

SLS managers believe NASA’s previous experience with DoD missions opens up the potential to carry out SLS launches with military payloads.

“Other missions which may utilize the SLS capability are launches for other Government agencies, like the DoD and any Government agencies with classified missions,” the Con Ops presentation noted.

“DoD mission support will also be available on the SLS, which will be available to partner with DoD and international partners for them to use SLS launch capabilities and opportunities. Classified missions have previously been supported through the MCC (Mission Control Center) at JSC (Johnson Space Center).

“This capability, along with the large payload capacity of SLS, allows for a wide range of DoD payload development and flight that was not previously available within the United States.”

The presentation also claimed the SLS’ large payload capability may be attractive to some commercial partners, citing Bigelow Space Station modules as one example.

It is likely the SLS team will wait until they know the outcome of the exploration roadmap evaluations before pursuing the potential of launching additional payloads.

(Images: Via L2 content, driven by L2′s SLS specific L2 section, which includes, presentations, videos, graphics and internal updates on the SLS and HLV, available on no other site. Other images via NASA and SpaceX.)

(L2 is – as it has been for the past several years – providing full exclusive SLS coverage, available no where else on the internet. To join L2, click here: http://www.nasaspaceflight.com/l2/)

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Musk was speaking to an audience at the AIAA Aerospace Sciences Meeting a few days ago, in a speech entitled “The Future of Space Launch: Where We’re Going and How to Get There.”

SpaceX is coming off the back of an encouraging conclusion to 2008, with the successful Flight 4 of their Falcon I launch vehicle, and progress towards the 2009 flight of their Falcon 9 launch vehicle. Space X also won 46 percent of NASA’s $.3.5 billion dollar Commercial Resupply Services (CRS) contract.

“2008 was a pretty busy year for SpaceX,” said Musk, using videos and slides ahead of a Q&A session. “We finally got into orbit and we’ve completed most of our development of our Falcon 9 schedule – which to give you a comparison; Falcon I can carry half a ton payload to orbit and Falcon 9 can carry 11 tons. It’s a pretty big step up in scale.”

The Falcon 9 vehicle will make its debut launch from Cape Canaveral, lifting off from a pad that was formerly used for the Titan 4 launch vehicles. Although it will take a number of flights, Musk has a goal of being able to roll out the F9, erect at the pad, tank, complete checkouts of the vehicle and launch in under 60 minutes. (Image left: SpaceX Falcon 9 Manned)

“The Falcon 9 tanks are all friction stir weld – and the F9 is largest fully friction stir welded structure in the world. The 180 feet long vehicle is assembled horizontally and the rolls out to the pad to be placed vertical for launch,” he noted.

“One of the goals I have for the Falcon 9 – which will take us many launches to achieve – is to have the vehicle out of the hanger and into the air in under 60 minutes.”

The launch date for Falcon 9′s debut remains fluid, although the vehicle itself is not the determining factor in trying to make a summer launch, claims Musk.

“We’re hoping for a summer launch of the Falcon 9, though I predict that is pending (based on) the development of its payload.”

Musk went on to speak about the Dragon capsule that will fly with the manned version of the Falcon 9, noting that SpaceX are looking to enable the vehicle to land anywhere in the world, by adding land landing capability. (Image Left: SpaceX Dragon splashdown).

NASA’s Orion lost nominal land landing capabilities via one of its numerous mass saving exercises – causes by performance shortfalls with the Ares I launch vehicle.

“There’s no major difference in appearance between the manned and unmanned version of Falcon 9, apart from the Launch Escape Tower (and the Dragon spacecraft for human passengers),” Musk noted.

“Dragon is designed for water landing, but could go to land landing later via airbags or a pneumatic piston that pulls on the chute. With that capability you can land almost anywhere, but currently the nominal landing site is just off the coast of California.”

A large part of the speech – the audio (50 minutes) and over 50 slides from the presentation are available on L2′s SpaceX subsection (only click if you are a L2 member) - was dedicated towards SpaceX’s full reusability ambitions, with hints towards using Falcon 1 as a test bed for “beefing up” protection on the stages to allow for reuse, before the full capability is added to the Falcon 9.

“The big thing that has to happen in space transportation is reusability. People sometimes use the Space Shuttle as an example, and say well gee, the Space Shuttle is so expensive and that was intended to be mostly reusable and doesn’t that prove that reusability is a bad idea?  I think that it’s really silly to extrapolate on a single data point.”

“If you look at any other mode of transportation like a bike or a horse, how many people would use that mode of transportation if it wasn’t reusable?

“Even if you make the vehicle very efficient, and create the most optimal trajectory, you are still only getting two to three percent of your launch mass to orbit.

“You have to make recovery systems robust enough to withstand re-entry and that is a very difficult problem – no one has really solved that problem yet. At SpaceX we’re trying to make the first stage reusable.

“With Falcon I’s fourth launch, the first stage got cooked, so we’re going to beef up the Thermal Protection System (TPS). By flight six we think it’s highly likely we’ll recover the first stage, and when we get it back we’ll see what survived through re-entry, and what got fried, and carry on with the process.

“That’s just to make the first stage reusable, it’ll be even harder with the second stage – which has got to have a full heatshield, it’ll have to have deorbit propulsion and communication.”

Musk also spoke about his wish to enable the first stage with flyback capability, but added that he would require a large sum of cash to achieve that goal.

“Any pound you use for reusability and re-entry (on the second stage) is a pound subtracted directly from payload, whereas first stage it’s a five to one ratio. This is a problem we’re trying to solve incrementally, but most exciting thing I’ve love to do is a flyback first stage. We’re just missing the billion dollars of capital it would take to try to do that.

“But that’s what SpaceX is aspiring to try and make this work, and I think if we show some progress and success, it would inspire other companies and other countries to try it as well.

“However, the goal for Falcon 9 is that it ends up being the first fully-reusable launch vehicle.” (Image Left: Inside Dragon capsule during ascent and Falcon 9 injecting Dragon into orbit).

Part 2 of Elon’s speech will follow in the coming days, in which he speaks on SpaceX’s association with NASA, the colonization of Mars, downstream satellite contracts, how suborbital is “little league”, and how he “wishes to affect the world in a positive way.”

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