They were delivered by a Pegasus rocket which was launched at around 40,000ft from a modified Lockheed TriStar.
A colleague walked up to me with his iPhone saying "Look, this is really cool" and I was surprised by the familiar sight of N140SC.
I had my reasons for being surprised. Firstly that it was still in operation after all these years, and also that there should still be media interest in it. After all, these launches have been going on since the late nineties.
More than surprised, however, I felt a sense of pride.
That's because I was part of the team of fitters and electricians who carried out the modifications to that aircraft.
All media coverage surrounding these launches focuses on the Pegasus delivery vehicle itself and its payload, with at best only passing mention of the converted TriStar.
Hardly surprising I suppose because big American companies like NASA and Orbital Sciences are unlikely to say "Special mention should go to the men at Marshall Aerospace in England, who made it possible for these high altitude launches to take place", are they?
While my own input was pretty minor in the scheme of things, it was still very necessary.
The Pegasus weighs 18,500kg plus payload (over 23,000kg for the Pegasus XL), so one thing that had to happen was that the TriStar needed to go on a serious diet to be able to lift it safely.
Myself and others were tasked with making this happen, so we set to stripping out the whole interior of the cabin. Everything had to come out, back to a bare airframe with just ducting and wiring looms left in the ceiling. Even the mid to rear passenger door mechanisms had to be stripped away to save weight - now they're just bolted in place permanently.
Apart from the two front cabin doors and the first twenty feet or so of cabin which houses crew seating and monitoring equipment, everything else is an empty shell. There's a lightweight partition separating the two areas, which me and my mate built.
I remember we ended up getting to know the design engineer pretty well during that part. We kept calling him over because his drawings didn't match up with the aircraft, and in the end he just said "Look, you build it, and when you've finished I'll come over and draw it", so that's what we did.
It may only have been tertiary structure, but we did our bit.
Towards the end of the job, there were countless drop tests carried out. With the aircraft on jacks, a huge steel cage full of concrete blocks to mimic the Pegasus was attached to the new release mechanism in the aircraft belly. With wooden blocks under the cage to absorb the impact and reduce the drop to a minimum, it was quite a sight to watch, with the whole aircraft shaking as over eighteen tonnes was released in a split second, accompanied by the deafening bang as the cage landed.
When Oscar (as it became affectionately know by the team, as it belonged to Orbital Sciences Corporation) went for its first test flight with a Pegasus attached, we went out to watch it take off with a distinct sense of collective pride.
As a team-building exercise, going to the woods to shoot your colleagues with paintballs had nothing on this.
We even had t-shirts made thanks to one of the guys who had a bit of artistic talent who drew a neat caricature of the plane with 'Oscar' under it.
So, as impressive as the Pegasus may be, this post is a shout out to everyone at Marshall Aerospace who made it all possible.