Seeing as i wasnt the one who made Powers: In Space, this storyline may not be the one that is used, but as far as it seems to be going it looks like it is. I put it on here so i dont forget at a later date.
On Earth NASA creates an expedition to go out and find alien life and other things. So upon a few months of being in cryosleep they finally unearth some proof of alien life. Not only that, but shortly after during their lunch they are picked up by a tractor beam onto one of the USA's spacestations. On the space station they eat some Berillian slugs, which triggered unknown anger, and Steve starts a fight by hitting a Viggor-Mehti for no reason at all, this upsets the USA and they do not take it lightly. Also the entire spacestation riots from the assault. Grashawk the Valverin, saw what Steve did and told the heroes to follow him. When Grashawk discovers that his ship has been stolen Tiffany offers him a ride in theirs, and they go to his home planet of Alavachi. Just before they land they were attacked by pirates, known as The Scarlet Hammer. After they repel the pirates by destroying their ship, they finally land on Alavachi, with some trouble because of the turbulence. But since they all worked as a team they survived the problem.
When they went out onto Alavachi, Grashawk takes them to see the warcheif, who said in order for them to be thought of as one with the society, they will have to go through a trial. Which was a massive arena battle, firstly it was with animals of the planet, lots of them. Then after a break they are pitted against 5 of the Valverins greatest warriors, and because of the telepathical link between a pack of Valverin, makes it alot harder than expected. With a few hard hits to both sides, they manage to defeat the Valverin and they are then accepted as one of the society. Emily and Nadia is granted access to the Valverins database, as they go around gathering information about other species, she gets really interested. She puts all the information on a disk, somehow, and keeps it in the ship under lock and key. Steve, Bart and Harold is given some fighting techniques known by the Valverin, which greatly improve their hand to hand fighting skills. Tiffany becomes quite a hero with the people of Alavachi as she goes to the hospital of the city and saves many lives. Alavachi is then attacked by the USA, as retaliation to the attacks that happened in the spacestation, but it is only a small force, the ship lands and the troops ravage the city, the heroes with the help of the Valverin, fight them. This involves the death of the warcheif, and Grashawk is elected warcheif of the race.
He then orders all able fighters to gather, train and get ready for war...