Soldiers have been stationed outside AWE Aldermaston & Burghfield, where Britain's nuclear deterrent is maintained.
New Stealth Fighters At Farnborough
The appearance of F-35 Lightning II stealth fighters will be among the highlights at Farnborough air show.
The supersonic jets are capable of short take offs and vertical landing, and will be displayed at the seven-day event in Hampshire which opens on Monday.
Defence Secretary Michael Fallon has described the F-35Bs - which are due to enter service with the Royal Navy and the RAF from 2018 - as ``the most advanced fast jets in the world''.
He claims they will ensure the UK has a ``formidable fighting force'' whether they operate from land or the new aircraft carrier fleet.
The Lockheed Martin-built aircraft were due to appear at Farnborough in 2014 but were grounded following an engine fire.
The show will also host British astronaut Tim Peake's first public appearance in the UK since returning to Earth from a six-month mission on the International Space Station.
He will take part in events on Friday - the final day of Farnborough's trade show - as well as on Saturday, when he will launch a flying display as the venue is opened up to the public.
US plane-making company Boeing will mark its 100th anniversary at the show.
Among the flying displays being carried out by the firm are the new 737 MAX and the 787-9 Dreamliner passenger airliners, and the F/A-18 and P-8A military aircraft.
Boeing's big rival Airbus, whose planes' wings are made in the UK, will display its A380 superjumbo as well as the A350 XWB (extra-wide bodied).
As is usual at the show - held every two years - Boeing and Airbus will vie for orders, although some experts predict that the size of the deals could be affected by the uncertainty in the wake of the EU referendum.
Farnborough's organisers said last month that over 90% of its exhibition space was sold, with 22 countries having their own pavilions, including the biggest ever Chinese presence.
David Cameron, who opened the previous show in 2014, has confirmed that he will return this year.
Speaking during Prime Minister's Questions in the House of Commons on Wednesday, he said: ``I think I'm one of the first prime ministers in a while to attend the Farnborough air show and I'm very happy to announce that I'll be going back there this year because I think it's very important.
``We have, I think, the second largest aerospace industry in the world after the United States and it's a brilliant moment to showcase that industry to the rest of the world and to clinch some important export deals both in the military and in the civilian space.''
The Red Arrows will not perform stunts at Farnborough for the first time in more than 50 years because of safety fears.
A decision was made to scrap the aerobatic displays following the Shoreham disaster last year, in which 11 people were killed.
The famous military planes will still carry out flypasts, but fans hoping to see loop-the-loops and barrel rolls will be disappointed after RAF bosses decided high-speed manoeuvres in such a built-up area were no longer appropriate.
Hybrid Air Vehicles announced that its Airlander, the world's largest aircraft, was unable to complete the minimum number of flying hours necessary for it to appear at the show.
Police say two men, arrested after reports of people acting suspiciously near barracks in Windsor, have no links to terrorism
Two men have been arrested after "acting suspiciously'' outside a barracks.
The UK's terror threat level's been raised to the highest possible. Here's what it means for the Thames Valley.
Recently Played Tracks
To listen live, choose your preferred station:
Now playing: The best feel good music
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.