Laravel 5 Form request, require input on create, but optional on edit

I am using laravel 5.6 resources controllers and form request the problem is that i have some inputs that are required on created, but on edit are optionals like file inputs. So i have this form request

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class ProgramRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            //
            'name.*'        => 'required',
            'description.*' => 'required',
            'logo'          => 'required|image|max:3000',
            'logo_alt'      => 'required|image|max:3000'
        ];
    }
}

the fields logo and logo_alt must be sent when creating the program, but when editing it sending a logo is optional.

is there a way to validate both cases with the same form request or i have to create a different form request for editing and for creating?

via Chebli Mohamed