Preview clip from Slingshot:
Reading the Radio Times description of the episode I wouldn't be surprised if it is very loosely based on the original episode series episode 'Sun Probe'.
Also another episode, 'Tunnels Of Time', will be shown on Sunday at 5.15PM.
The production crew have stated that 'Fireflash' is based on 'Trapped in the Sky'. About 32 and a half minutes in this youtube video