There are 20 objects in orbit associated with the Falcon 9 v 1.1 launch. So far only 1 has been identified. 5 were payloads of the launch, plus the booster and some debris. Bottom line, 11 objects were expected, and 9 are unexpected. What are the other objects?


2 Answers 2


UPDATE 2013-10-13

The latest update names B as CUSat 1 and C as DANDE. All payloads have now been identified. Interestingly, they say CUSat-2 is attached to the upper stage (object G). Everything after object G is identified as debris. Additionally, there are now 26 total objects cataloged, with debris pieces labeled H-AB.

It helps to understand what was expected in the first place. Here's a list of the payloads:

Cassiope (1 piece expected) - the primary payload.

DANDE (2 pieces expected) - According to their website, DANDE separates from the upper stage with a lightband adapter bracket, which then separates from the spacecraft itself. Apparently, this separation has not yet occurred, according to the DANDE team.

POPACS (7 pieces expected - 3 spheres, 4 spacers)

CUSat (only 1 piece expected - NOT 2 as reported elsewhere) - the linked article has details about the decision to keep them mated.

Total: 11 objects associated with the payloads. We can add one for the rocket body, bringing us to 12 expected objects, and 8 unknowns. The fairing was separated before the vehicle reached orbit, as is typically the case.

As @PearsonArtPhoto stated, Objects A-F would be the payloads, and G has been identified as the upper stage. In fact, it has recently been confirmed that A is Cassiope, and D-F are the three POPACSS spheres.

Now that that is all cleared up, it brings us to your actual question: what's everything else? To clarify, it is somewhat rare for a so-called successful launch to result in more tracked objects than expected, so the fact that there's even one extra object is noteworthy. @PearsonArtPhoto did a good job looking at the orbits of the unknown objects, so instead I'll focus on speculating about the source of the pieces.

SpaceX has not yet released much information about the upper stage test fire, other than there was an anomaly, and no explosion. The spread of the unknown objects is troubling - energy was added to them in some way - either through a short second burn (before it shut down) or via an explosion of some kind - even just a tank rupture. According to Jonathan McDowell, the delta-V for the scatter is about 60 m/s, which is quite significant.

A couple of the objects have/had very large decay rates, indicating that they are likely the pieces of insulation that SpaceX posited. However, many of the unknown objects have not yet decayed, so they likely have a higher ballistic coefficient (mass/cross sectional area), i.e. they are more dense than typical insulation. It's possible that there were other pieces associated with the secondary payloads, but something "coming loose" from an upper stage (and not causing other, bigger problems) would be a pretty egregious fault, and I think it's unlikely.

In my opinion, there was some sort of energetic event immediately following the upper stage firing attempt, resulting in several debris pieces.

Bottom line: SpaceX may not be talking much, but there are lots of people paying attention and trying to figure this out (including the Air Force... eventually).


Here's what's known about them, from a bit of analysis.

  1. Object G is the booster. It has the largest RCS, and JSPOC has identified it as such.
  2. A-F would be likely candidates for the primary payloads. They are grouped closely to the rocket booster, occupying a similar orbit. There were 5 payloads, plus there might have been some sort of a payload adapter. JSPOC seems to think they might be important, as it put them ahead of the object booster. Normally the order is payloads, separation hardware, booster stages, and debris.
  3. There appears to generally speaking be 2 groups of objects, in 2 distinct orbits. Even early on, as seen below, this separation occurred. Objects H, J, K, L, and U all seem to be in a similar orbit to the booster and payloads, while objects M, N, P, Q, R, S, T, and V appear clustered together behind.
  4. On October 1, Object U is shown to be decaying significantly. I suspect that this object should have been grouped with the earlier objects, perhaps paired with Object K, both being a payload fairing.
  5. Objects M, N, P, and V have a higher perigee than the payloads. I don't know what this indicates, but it is curious.
  6. Objects R, S, and T look like they are rapidly decaying, indicating that they are light. They are on a rapid return course, looking to re-enter no later than this weekend.
  7. Object I became U, O became V, to avoid confusion (Chris in chat).

Separation of satellites enter image description here

Bottom line:

  • A-F are primary payload or related.
  • G is the rocket booster
  • U and K are likely payload fairings
  • R, S, T are light quickly decaying objects. These are likely additional debris created along the way, before the rocket stopped firing, or when the rocket stopped firing (If given some impulse from the rocket as it stopped)
  • H, J, and L are likely objects separated during the deployment of the satellites.
  • M, N, P, Q, and V are a mystery.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.